Apparatus for swaging tubular blanks



Nov. 6, 1945. F. J. RODE ETAL APPARATUS FOR SWAGING TUBULAR BLANKS Filed Jan. 2, 1943 2 Sheets-Sheet l INVENTOR.

ATTQRNEIYS Nov. '6, 1945. F. J. RODE ET AL 2,388,643

I APPARATUS FOR SWAGING TUBULAR BLANKS Filed Jan. 2, 1943 2 Sheets-Sheet 2 NOE Q INVENTOR. FREDRICH J. RODE and HATCH Mam MERE ITH BY J J .AIT RNEQ Patented Nov. 6, 1945 UNITED STATES PATENT OFFICE APPARATUS FOR SWAGING TUBULAR BLAN Fredricli J. Rode and Meredith R. Hatch, Toledo, v Ohio, assignors to E. W. Bliss Company, Brooklyn, N. Y., a corporation of Delaware Application January 2, 1943, Serial No. 471,204

2 Claims. (Ci. Sit-12) This invention relates, as indicated, to apparatus for swaging tubular blanks, but has reference more particularly to the production of tubular blanks having tapered or swaged end portions which are especially adapted for formation into propeller blades and the like. 7

In the manufacture of propeller blades from seamless tubing and the like, it is necessaryto out such tubing into pieces or blanks of the desired length and to swage or otherwise reduce a portion of such blanks to provide hub portions of smaller diameter, so as to adapt the propeller, when ilnally formed, for attachment to a suitable hub.

Various methods have beenused and tried for the reduction of the hub end of the blank to the desired diameter, but all of these have involved operations or stepswhich have not permitted the material of the tubing to flow properly andeasily during or incident to the reduction. Such methods as have been used for this purpose have, moreover, been slow and laborioua and have involved heavyexpensive forming or reducing machines.

The present invention has, as its primary object the reduction of the end portions of tubular blanks and the like by a method which permits the material of the blank to floweasily and naturally s as to facilitate and greatly increase the production of propeller blades and the like to the quantities necessitated by the exigencies of the war.

Another object of the invention is to provide machines or devices of novel construction which are especially adapted for the practice of the aforesaid method.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described andparticularly pointed out in the claims; the annexed drawings and the following description setting forth in detail certain means and one mode of carrying out the invention, such disclosed means and mode illustrating, however, but one of various ways in which the principle of the invention may be used.

In said annexed drawings:

Fig. 1 is an end elevational view of one form of an apparatus or device which is adapted for the practice of the method of the present invention;

Fig. 2 is a longitudinal cross-sectional view of the device of Fig. 1, taken on the line 2-2 of Fig. 1, and showing also the finish of the operation of tapering a portion of a tubular blank by means of the device;

Fig. 3 is a fragmentary top plan view of the device shown in Fig. 2, but with a somewhat modified arrangement of the swaging discs or dies;

Fig. 4 is a fragmentary view similar to Fig. 2, but showing a somewhat modified construction;

Fig. 5 is a view similar to Fig. 1, but showing another modification in the arrangement of the swaging discs or dies;

Fig. 6 .is afragmentary cross-sectional view, taken on the line 66-of Fig. 5, and

Fig. 7 is a view of one of the swaging dies or discs.

Referring more particularly to Figs. 1 and 2 of the drawings, a device constructed in accordance with the invention comprises a chuck I of generally cylindrical form, consisting of ends 2 and 3, and a cylindrical body from which portions have been removed to leave connecting ribs 4 of a'rcuate cross-section for the ends 2 and 3, and provide openings or spaces 5 therebetween, through which the tube swaging operation may be observed.

The end 2 of the chuck has a hub 6 extending therefrom, to which a tapered hollow driving spindle 1 may be attached by means of screws 0,

the spindle being adapted for insertion in a conventional machine tool, whereby the chuck may be rotated. If'desired "spindle 1 may comprise the spindle of a swaging machine and is shown as being hollow to permit the reduced tube portion to extend therein.

The end 2 of the chuck is also provided with inwardly extending bosses or projections 9, shown here as three in number and spaced degrees apart circumferentially of such chuck end. These bosses providesupports for the inner ends of hollow shafts I0, preferably formed of bronze or the like, and the outer ends of which are supported in hub like enlargements ll of the end 3 of the chuck. The shafts l0 are not necessarily arranged parallel with the axis or the chuck, and can be retained against axial displacement by means of set screws I2.

Mounted upon each of the shafts Ill between the bosses 9 and enlargements II is a multiplicity of swaging discs or dies l3, some of which are of different diameter than the others, so as toprovide between the three sets of dies a throat I! for the reception of the tubular blank to be swaged, the diameter and arrangement of the dies and consequently the contour of the throat llbeing determined by the taper or shape de- The swaging dies l3 are freely revoluble about the shafts upon which they are mounted and are spaced apart by means of washers l 5, preferably formed of bronze or the like; and adapted to engage hub-like enlargements [3' (see Fig, '7) on the dies.

An annular guide plate or member 16 is secured as by screws I! to the end 3 of the chuck, in alignment with the throat H, and has a beveled surface I8 adapted to facilitate insertion of the tubular blank B into the throat ll.

As best shown in Fig. 7, each of the dies I3, has a peripheral surface portion l9, which tapers at a slight angle a to the axis of the die, and inwardly towards the entering end of the throat ll, This angle varies, depending upon the contour desired in the throat. For swaging propeller blanks, this angle may vary from zero degrees to about 5 degrees. Each die, moreover, is provided with a surface 20', which is beveled or rounded, so as to facilitate movement of the tubular blank into the chuck.

In operation, the tubular propeller blank B, which is to be swaged to provide the tapered end B for attachment to a propeller hub is caused to enter the member I6 and throat ll while the chuck as a whole is being rotated about its axis. This causes the dies to gradually swage the end portion B of the blank. The coaction of the dies I: with the blank during this operation causes a swaging action which is gradual and occurs in an easy and natural manner, and without the expenditure of an undue amount of force. The tapered faces I! of the dies, and the fact that the dies are freely revoluble about their shafts during rotation of the chuck greatly facilitates the swaging action. This swaging action is also facilitated by virtue of the spaces between the dies, which permits the metal of the blank, as it is being swaged, to flow into such spaces to a slight extent in its passage from one die to another.

The chuck, as a whole, is preferably made from cast iron, while the dies are preferably made from a wear-resistant ferrous alloy, such, for example, as Mecanite."

It is apparent from the foregoing that a means has been provided whereby the production of propeller blades may be increased to a point commensurate with the great demands made for such blades arising outof the present war.

If desired, the chuck I may be maintained stationary, instead of being rotated, and the blank rotated as it is being swaged. In that event, the blank will be mounted on a suitable chuck which has a rotary movement imparted thereto by the machine tool, such chuck moving toward the swaging chuck as the blank is being swaged.

In Fig. 3, a modification of the throat and die arrangement is shown, more or less diagrammatically, in which the dies are mounted on shafts, which are mounted in the chuck at a slight angle to a line L which is normal to the ends of the chuck. This angle need not be more than about 015', as indicated in that figure, but may be varied to suit a particular job or contour.

As a result of this arrangement, which is in effect a spiral arrangement of the sets of dies, the blank, as it is being swaged, has a slight longitudinal feeding movement into the throat imparted thereto, which further facilitates the swaging operation. Swinging this axis displacement in the opposite direction would reverse this feeding influence.

In Fig. 4, the arrangement of the dies is somewhat similar to that shown in Fig. 2, but in this case, the chuck consists of two parts, the inner one of which consists of two ends 2' and 3' joined together as a unit by the die shafts l0, and the outer one of which consists of a cylindrical member l, which is revolubly mounted on the inner unit by means of tapered roller bearings 20 and 2|. The inner unit ma be maintained stationary during the swaging operation, in which event, the blank B will be rotated as it is being swaged, and the member 4' will be rotated as a result of the swaging operation, due to the pressure exerted by the blank upon the dies l3 and by the dies, in turn, upon the member 4', which constitutes in effect, an'outer race for such dies, the inner surface 22 thereof being contoured to the contour presented by the dies to provide a raceway for the latter. The member 4', in other words, takes up the thrust of the dies incidental to the swaging operation and thus greatly facilitates such operation,

' If the inner unit of the arrangement shown in Fig. 4 is rotated during the swaging operation, theouter member 4' may or may not rotate, depending upon the pressure exerted thereon by the dies. Being mounted on bearings, however, it is free to rotate at all times. This race may be incorporated in a head design comprising an integral part of member 2 if desired.

In Figs. 5 and 6, a modified form of construetion is' shown, in which six sets of dies are employed, the sets being spaced apart circumferentially from each other 60 degrees. The dies in each set are arranged in staggered or offset relation to those in the adjacent sets and for this purpose, collars 25 are inserted between the dies to provide space for the interleaving of the dies. In this arrangement, certain advantages are secured in that the sets of dies engage the blank B at points only 60 degrees instead of degrees apart. This, under certain conditions, produces a more uniformly swaged blank.

The swaging operations may be performed with the tubular blank either hot or cold, and it will be understood that while the aforesaid description refers generally to the swaging of tubular blanks, that'it may also be used for swaging solid rods or other bar shaped products, as well as various semi-finished articles which require swaging in their manufacture into finished articles.

The multiplicity of rolls spaced about the perimeter of the tube to be swaged have a tendency to form a thread or threads which brings about a tendency to draw the tubular piece into the roll carrying head. It will be apparent to those skilled in the art that stages of rolls can be arranged in the head which by reason of having axes set at the slight angle to the center line of the work piece brings about the mentioned spiral forming tendency while other sets of rolls can be arranged on parallel axes to effect a close finishing of the completely reduced portion of the work piece.

Other forms may be employed embodying the features of our invention instead of the one herein explained, change being made as regards the means and the steps herein disclosed, provided the elements stated by any of the following claims or the equivalent of such stated elements be employed.

We therefore particularly point out and distinctly claim as our invention:

1. In a device of the character described, a chuck comprising a rotatable inner portion having a plurality of circumferentially-spaced shafts mounted therein and an outer portion revoluble relatively to said inner portion, and a set of disklike dies mounted on each shaft, said outer portion of the chuck having an inner wall engageable by said dies.

2. In a device of the character described, a chuck comprising an inner portion formed of two parts interconnected by means of shafts, an outer portion revoluble through at least 360 degrees relatively to said inner portion, rotary swaging dies mounted on said shafts between said parts of the inner portion, said dies having the peripheries thereof in engagement with the walls of said outer portion, and means for positively rotating said inner portion.

FREDRICH J. RODE.

MEREDITH R. HATCH. 

